Photodiodes are employed to convert received light photons to electrical signals than can be detected by electronic detection circuits. To increase the efficiency of the photodiodes, a reverse bias voltage is applied across the photodiode. An inverting switching regulator is often employed to provide a negative voltage for the reverse bias voltage. Due to cost restrictions, the switching regulator can be integrated onto an analog integrated circuit dedicated to providing the voltage supplies for the system. The substrate of the integrated circuit is grounded. Conventional circuits directly use the output of the inverting switching regulators as the source of negative voltage. However, the ripple generated on the switching regulator output exclude it from being used directly on the anode of the photodiode which can couple noise to other sensing circuits. If noise is coupled though the photo-diode and sensed by a very high-gain transimpedance amplifier (TIA), for example, this can cause detection problems in the circuit.